Many solutions are known from the state of the art, in the case of which automatic floor cleaning machines carry out cleaning processes on floors of buildings independently. There are two approaches, which have their own individual character. In the case of the first approach, the floor surface is traversed at random, for example in that a random change of direction is chosen when striking an obstacle. Due to the fact that a map of the room, which is to be cleaned, and a plan for an advantageous cleaning route is not created, the required storage capacity is small, but the effort for the processing movement is very high. Many areas are traversed several times and a long cleaning time must be provided for cleaning as completely as possible. This method is not suitable for professional cleaning.
In the case of the second approach, the floor surface is mapped as accurately as possible and an advantageous route is determined. It must be controlled that the planned route is followed in response to the cleaning. In addition, a solution for bypassing obstacles and the subsequent location of the planned route must be provided. These solutions use grids for storing the map of the room, for planning the cleaning route and for storing the cleaned areas. Due to the fact that the resolution of the grid must be as small as possible, correspondingly large amounts of data quantities must be stored and processed.
U.S. Pat. No. 5,279,672 describes a cleaning robot, which comprises a housing, two drive wheels, two support wheels, rotatable cleaning brushes on the front side, comprising a cleaning liquid supply, a suction device for extracting the contaminated cleaning liquid on the rear side. A control device comprising sensors is used to control the movement of the cleaning robot. An infrared laser scanner, which reads barcode information from the reflecting targets, which are arranged on the room boundaries, is arranged on the upper side of the cleaning robot. The reflecting targets make it possible for the cleaning robot to determine its position and the current cleaning area by means of a triangulation. For accurately detecting the position, the laser scanner must detect the angular position of at least 3 different targets simultaneously. Without recognizing three targets, the robot continues to drive for a predefined distance and if it has then still not detected three targets simultaneously, it discontinues the cleaning operation and transmits an alarm signal. When the robot can detect its position and the cleaning area, it must follow a previously programmed cleaning plan, wherein, when approaching an adjustable obstacle or element, respectively, the robot attempts to bypass said obstacle. This solution has the disadvantage that the targets with their barcodes must first be mounted and that a cleaning plan must additionally be programmed for each room. In the event that mobile elements are placed in front of targets, the cleaning robot can no longer clean automatically.
EP 0 635 773 B1 describes a method for creating an environment map and for determining a position for mobile units, which move in an unknown environment. To correct the position of the mobile unit in the environment map and the position of a landmark in the environment map, a certain distance to the landmark is predicted starting at a certain position based on the movement history, and a certain distance to the landmark is measured based on the current position. The difference between the predicted and the measured distance to the landmark is identified as system error. Knowing the uncertainty, which occurs in response to determining the position of the mobile unit and in response to determining the location of the landmark, the system error is divided in the ratio thereof and is used to correct the position of the mobile unit and of the location of the landmark in the environment map. Uncertainties during the movement of the mobile unit can thus be reduced. Even though the mounting of targets is foregone herein, the orientation nonetheless takes place on narrowly bounded landmarks, which can often be covered in rooms comprising movable obstacles.
EP 1 903 413 A2 describes the creation of a map, wherein occupied points are entered into a grid and the thickness of the obstacles and of the wall are increased in accordance with the expansion of the robot, so that the robot can be moved on the map as a point without an expansion. A map, on which the room boundaries are entered as occupied grid points, always has an inaccuracy in accordance with the cell size of the grid and leads to large data quantities, because the grid must be sufficiently fine, so that the boundary can be entered to a sufficiently accurate extent. A further disadvantage of the described solution is that the controller of the robot determines a cleaning direction and that a defined route must be driven in accordance with the predetermined cleaning direction. To carry out these steps, the controller must store large data quantities and must make extensive calculations.
U.S. Pat. No. 8,060,254 B2 also describes distance measurements for bordering a room to obtain grid points. Feature points are extracted from the grid points of the boundary. A position estimate and feature points are updated by means of a simultaneous localization and map building algorithm (SLAM). A sweeping direction is determined from the most frequent direction of the boundary and the grid is placed according to the sweeping direction. A map, on which the room boundaries are entered as occupied grid points, always has an inaccuracy according to the cell size of the grid and leads to data quantities, which are undesirably high. A further disadvantage of the described solution is that a cleaning direction must be determined from the boundary or from the map, respectively.
EP 1 557 730 A1 describes a solution, in the case of which the processing device creates a grid map of the room and divides the room into a plurality of partial segments, which are then processed subsequently by means of a predetermined movement pattern. The position of the processing device is thereby determined by means of reference points, which were determined from the outer contour of the room. The data effort for the map and the provision and control of the movement pattern is also very extensive herein.
In stores, it is possible for display stands, guide signs, pallets, containers or products to be arranged directly on other areas of the floor surface again and again. Accordingly, completely different free floor surfaces are to be expected again and again for the cleaning in predetermined time lags. The solutions for the professional automatic cleaning, which are known from the state of the art, would have to newly map the respective new situations again and again, which is associated with an unreasonable effort. This is why automatic cleaning devices are not used in stores.
Automatic floor treatments are not limited to cleaning. For example, a treatment, such as the polishing of the floor surface or the application of a surface coating, can also be carried out by an automatic floor treatment machine. The term floor treatment also includes controlling the floor surface or carrying out measurements, respectively, on the entire floor surface. Such measurements can be associated with treatments on selected locations. Floor surfaces do not only refer to surfaces in rooms, but also to surfaces outside, wherein positioning areas can then surely be provided for the position determinations instead of the walls, columns or other orientation elements, so as to carry out distance measurements thereon. The floor treatment outside can comprise everything ranging from mowing lawn, working soil, fertilization, sowing, weed treatment, harvesting, to searching for metal parts or even mines.